In overhead sprinkler irrigation systems, water is pumped from wells, rivers, lakes, and other open bodies of water. Typically, the water carries dirt, rust, and other debris which clog the orifices of the spray nozzles. This clogging results in uneven water application on the field.
Heretofore, this problem has necessitated manual clearing of clogged orifices by the user. Because these systems typically have from 30 to as many as 200 spray nozzles, this manual clearing becomes a tedious and time-consuming task. The principal object of this invention, therefore, is to provide a filter which will prevent the water-borne debris from reaching the nozzle.
These overhead sprinkler irrigation systems are designed to effect a precise application of water on the field by use of nozzles which have orifices sized to a specific gallons per minute output. There are currently many sizes of nozzles manufactured. It is a further object of this invention that the filter be compatible with these existing nozzles.
Normally, these systems are in operation 24 hours a day for days at a time between shutdowns. Therefore, it is another object of this invention to provide storage space within the body of the filter for an accumulation of debris. Additionally, it is an object of this invention to provide an automatic self-flushing of the accumulated debris from the filter at shutdown and start up of the system.
A further object of this invention is to provide a debris outlet of sufficient size to allow particles of debris as large as 3/8 inch in size to pass therethrough.
Additional objects are to design a new and improved automatically self-flushing filter which is simple and durable in construction, efficient and reliable in operation, eliminates constant maintenance and servicing, and is economical in cost.
While the prior art is replete with designs for self-cleaning shower heads, self-cleaning filters, and the like, none are entirely suitable for use on overhead sprinkler irrigation systems.
The prior art devices, such as those shown in Filliung et al (U.S. Pat. No. 2,770,498, Automatic Self-Cleaning Shower Heads, 1956) and Bielka (U.S. Pat. No. 4,717,073, Sprayer Head, 1988) typically include spray diffusers as an integral part of their design. Therefore, they would not be compatible with the nozzles already in use on the systems. Additionally, there is no provision for storage of accumulated debris. Moreover, the prior art devices do not allow for passage of the larger particles of debris.
While the filtering device shown in Gilger (U.S. Pat. No. 4,064,046, Self-Cleaning Filter Apparatus, 1977) allows for connection to any nozzle and for storage of accumulated debris, the need to visually check and manually service it makes it undesirable. Further, the size and configuration of this device makes it impractical for use on an overhead sprinkler irrigation system.